March 1, 2007

scientists react to evidence supporting ‘soft’ IVF

The Science Media Centre asked an expert on obstetrics and gynaecology to comment on this paper published in the Lancet.

William L Ledger, Professor of Obstetrics and Gynaecology, University of Sheffield, said:

“This paper describes a well constructed randomised trial that supports the concept of ‘soft’ IVF. Women are always reluctant to inject fertility drugs, and doses have been steadily reducing over the last few years. The drug doses used in this paper are probably as low as can be achieved at present, without a major negative impact on pregnancy rates. Not only is this more acceptable to patients, it also reduces risk of ovarian hyperstimulation, an unpleasant side effect of drug treatment that has led to fatalities in the past.

“The authors have also shown that we can achieve as many pregnancies without high risk of multiple birth if we put back one embryo at a time. This practice will cut the costs of IVF to NHS considerably, by avoiding the high costs of intensive care for premature babies born too soon because they are twins.

“We now need to convince patients that IVF is not a ‘sprint’ – don’t put all your hopes into the ‘fresh’ IVF cycle – embryo freezing is cheap, safe and the transfer of thawed frozen embryos is usually done in the woman’s natural cycle without any drugs and with minimal monitoring. This makes frozen embryo transfer practically stress free and if the frozen embryos are replaced one at a time in natural cycles then the couple have the same chances of a baby as if they had two put back in the fresh cycle.

“Maybe in the future we’ll not put embryos back in the fresh cycle at all, disconnecting the processes of egg collection from embryo transfer all together by freezing all the embryos and using the woman’s natural cycle for transfer. This would reduce risks of hyperstimulation even further.”